My daewoo microwave/toaster blew my breaker upon resetting it and plugging in the microwave it blew again then it tripped my GFI what could be the problem?

A number of kitchen outlets may have GFI switches, especially if they are anywhere near sinks. The GFI may have been tripped. There should be a reset switch in the middle of the plug. See if it's tripped, and reset if necessary.

The breaker may have been tripped. Most kitchen circuits are wired to 20Amp breakers. If this is elsewhere in the house, like in an entertainment room or such, it is likely a 15 Amp outlet. Microwaves can draw a fair amount of power. Someone using another kitchen appliance, hair dryer, or what have you, on the same circuit, may have tripped the breaker. Newer code may specify an AFI or GFI breaker for kitchen outlets. In that case, a fault with something else on the circuit may have tripped the breaker. If that is the case, and it trips again, talk to an electrician. You don't want a fault like that undiagnosed.

3) You may also want to try plugging the microwave into another outlet, even if the normal outlet seems OK

If there's wall power and a good plug-in, then you work back to the microwave itself. A number will have fuses. Also, there may be interlocks that kick in if, for instance, the carousel rotation is impeded - that can mean something on the carousel is hitting a wall, which can risk tipping something over and spilling, or risk mucking up the reduction gears for the carousel axle if it keeps pushing.

At that point, looking for specifics on your microwave model will be needed. You may also try the Microsoft Support approach - i.e unplug it for 5 minutes, then plug it back in and see if it works.

Hoping this helps, Good Luck!